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181.
Wei-Jen Chen Chin-Lung Chiang Hsu-Chiang Kuan Ming-Chuen Yip 《Journal of Physics and Chemistry of Solids》2010,71(4):431-435
The surface carbon nanotubes (CNTs) were modified to generate functional reactors by using the sonicication method to distribute CNTs evenly among epoxy resin, which was prepared into nano-prepreg with carbon fibers. Additionally, based on various proportions of modified and unmodified CNTs, the mechanical properties and conductivities of the composite, as well as, the characteristics of material subjected to various temperature conditions were investigated. Experimental results indicate that increasing CNT content enhances the mechanical strength and electrical properties. At various temperatures, the mechanical strength drops with increase in temperature because different expansion coefficients differ between fiber and epoxy resin. Finally, the failure surface of nanocomposite was examined using scanning electron microscopy (SEM). Finally we provide a discussion of the failure mechanism of the material. 相似文献
182.
An erbium-doped fiber laser (EDFL) constructed in a master oscillator and power amplifier (MOPA) configuration is analyzed. The pump powers for the fiber cavity laser and the booster amplifier stages are managed properly to achieve maximal pump conversion efficiency. Our design achieves a pump conversion efficiency of 91.4%, corresponding to a quantum efficiency of 96.6%, for a 1565.8 nm MOPA laser pumped by a total power of 300 mW at 1480 nm. The optimized MOPA laser shows a 25% enhancement in the pump conversion efficiency, compared to a non-MOPA fiber laser. A side lobe suppression ratio of 48 dB for the optimized MOPA laser is observed. 相似文献
183.
Nishimura K Browder TE Adachi I Aihara H Arinstein K Aushev T Bakich AM Balagura V Barberio E Belous K Bhardwaj V Bischofberger M Bondar A Bozek A Bračko M Chang MC Chao Y Chen A Chen KF Chen P Cheon BG Chiang CC Cho IS Choi Y Dalseno J Danilov M Doležal Z Drutskoy A Eidelman S Gabyshev N Golob B Ha H Haba J Hara T Hayasaka K Hayashii H Horii Y Hoshi Y Hou WS Hyun HJ Iijima T Inami K Itoh R Iwabuchi M Iwasaki Y Joshi NJ Julius T Kang JH Kapusta P Kawai H Kawasaki T Kichimi H Kiesling C Kim HJ 《Physical review letters》2010,105(19):191803
We report a first measurement of inclusive B→Xsη decays, where Xs is a charmless state with unit strangeness. The measurement is based on a pseudoinclusive reconstruction technique and uses a sample of 657×10(6)BB pairs accumulated with the Belle detector at the KEKB e+e- collider. For MXs < 2.6 GeV/c2, we measure a branching fraction of [26.1±3.0(stat)-2.1+1.9(syst)-7.1+4.0(model)]×10(-5) and a direct CP asymmetry of ACP=-0.13±0.04-0.03+0.02. Over half of the signal occurs in the range MXs > 1.8 GeV/c2. 相似文献
184.
Esen S Schwartz AJ Adachi I Aihara H Arinstein K Aulchenko V Aushev T Aziz T Bakich AM Balagura V Barberio E Bay A Bischofberger M Bondar A Bozek A Bračko M Browder TE Chang MC Chang P Chen A Chen P Cheon BG Chiang CC Choi Y Dalseno J Dash M Doležal Z Drásal Z Drutskoy A Eidelman S Goldenzweig P Golob B Ha H Haba J Hara T Hayasaka K Higuchi T Hoshi Y Hou WS Hsiung YB Hyun HJ Iijima T Inami K Itoh R Iwabuchi M Joshi NJ Julius T Kang JH Kawasaki T Kichimi H Kim HJ Kim HO Kim JH Kim YJ Kinoshita K 《Physical review letters》2010,105(20):201802
We have made the first observation of B(s)(0)→D(s)(*)+ D(s)(*)- decays using 23.6 fb(-1) of data recorded by the Belle experiment running on the Υ(5S) resonance. The branching fractions are measured to be B(B(s)(0)→D(s)+ D(s)-)=(1.03(-0.32-0.25)(+0.39+0.26))%, B(B(s)(0)→D(s)(*±) D(s)(?))=(2.75(-0.71)(+0.83)±0.69)%, and B(B(s)(0)→D(s)*+ D(s)*-)=(3.08(-1.04-0.86)(+1.22+0.85))%; the sum is B[B(s)(0)→D(s)(*)+ D(s)(*)-]=(6.85(-1.30-1.80)(+1.53+1.79))%. Assuming B(s)(0)→D(s)(*)+ D(s)(*)- saturates decays to CP-even final states, the branching fraction determines the ratio ΔΓ(s)/cosφ, where ΔΓ(s) is the difference in widths between the two B(s)-B(s) mass eigenstates, and φ is a CP-violating weak phase. Taking CP violation to be negligibly small, we obtain ΔΓ(s)/Γ(s)=0.147(-0.030)(+0.036)(stat)(-0.041)(+0.042)(syst), where Γ(s) is the mean decay width. 相似文献
185.
Chin-Tsang Chiang Shao-Hsuan Wang Ming-Yueh Huang 《Annals of the Institute of Statistical Mathematics》2018,70(3):523-551
One attractive advantage of the presented single-index hazards regression is that it can take into account possibly time-dependent covariates. In such a model formulation, the main theme of this research is to develop a theoretically valid and practically feasible estimation procedure for the index coefficients and the induced survival function. In particular, compared with the existing pseudo-likelihood approaches, our one proposes an automatic bandwidth selection and suppresses an influence of outliers. By making an effective use of the considered versatile survival process, we further reduce a substantial finite-sample bias in the Chambless-Diao type estimator of the most popular time-dependent accuracy summary. The asymptotic properties of estimators and data-driven bandwidths are also established under some suitable conditions. It is found in simulations that the proposed estimators and inference procedures exhibit quite satisfactory performances. Moreover, the general applicability of our methodology is illustrated by two empirical data. 相似文献
186.
Y. Chiang 《Journal of Global Optimization》2010,46(3):465-473
In this paper, we derive an existence result for generalized variational inequalities associated with multivalued mappings
on weakly compact sets under a continuity assumption which is much weaker than the regular complete continuity. As an application,
we prove the existence of exceptional families of elements for such mappings on closed convex cones in reflexive Banach spaces
when the corresponding complementarity problems have no solutions. 相似文献
187.
Transversal wave maps and wave maps are different. There are wave maps which are not transversal wave maps, and vice versa. However, if f is a wave map under certain circumstance, then f is a transversal wave map. We show that if f is a transversal exponential wave map, then the associated energy–momentum is transversally conserved. We finally obtain the relationship among transversal wave maps, transversal exponential wave maps and certain second order symmetric tensors. 相似文献
188.
Wei-Yin?Chiang Pik-Yin?LaiEmail author Chi-Keung?Chan 《The European Physical Journal B - Condensed Matter and Complex Systems》2013,86(7):327
Coupled excitable elements in the presence of noise can exhibit oscillatory behavior with non-trivial frequency dependence as the coupling strength of the system increases. The phenomenon of frequency enhancement (FE) occurs in some coupling regime, in which the elements can oscillate with a frequency higher than their uncoupled frequencies. In this paper, details of the FE are investigated by simulations of the FitzHugh-Nagumo model with different network topologies. It is found that the characteristics of FE, such as the maximal enhancement coupling, enhancement level etc, are functions of the network topology and spatial dimensions. The effect of excitability and the spatio-temporal patterns during FE are investigated to provide an intuitive picture for the enhancement mechanism. Interestingly, some of these characteristics of FE can be described by scaling laws; suggesting the existence of universality in the FE phenomenon. The relevance of these results to biological rhythms are also discussed. 相似文献
189.
Network DEA pitfalls: Divisional efficiency and frontier projection under general network structures
Data envelopment analysis (DEA) is a method for measuring the efficiency of peer decision making units (DMUs). Recently network DEA models been developed to examine the efficiency of DMUs with internal structures. The internal network structures range from a simple two-stage process to a complex system where multiple divisions are linked together with intermediate measures. In general, there are two types of network DEA models. One is developed under the standard multiplier DEA models based upon the DEA ratio efficiency, and the other under the envelopment DEA models based upon production possibility sets. While the multiplier and envelopment DEA models are dual models and equivalent under the standard DEA, such is not necessarily true for the two types of network DEA models. Pitfalls in network DEA are discussed with respect to the determination of divisional efficiency, frontier type, and projections. We point out that the envelopment-based network DEA model should be used for determining the frontier projection for inefficient DMUs while the multiplier-based network DEA model should be used for determining the divisional efficiency. Finally, we demonstrate that under general network structures, the multiplier and envelopment network DEA models are two different approaches. The divisional efficiency obtained from the multiplier network DEA model can be infeasible in the envelopment network DEA model. This indicates that these two types of network DEA models use different concepts of efficiency. We further demonstrate that the envelopment model’s divisional efficiency may actually be the overall efficiency. 相似文献
190.
Jia-Wen Yao Wei-Chiung Chi Jing-Hao Xu Gene-Hsiang Lee Michael Y. Chiang Bo-Rong Peng Nai-Cheng Lin Chiung-Chin Hu Lee-Shing Fang Guo-Qiang Li Yu-Chia Chang Tsong-Long Hwang Ping-Jyun Sung 《Tetrahedron》2019,75(11):1510-1516
A known briarane, brianthein W (1), along with four new hydroperoxybriaranes, briaviolides R–U (2–5), have been obtained from the octocoral Briareum violaceum. The absolute configuration of 1 was determined by X-ray analysis for the first time and the structures of briaranes 2–5 were established by spectroscopic methods. Bioactivity study showed that briarane 3 decreased the production of superoxide anions from human neutrophils. 相似文献